Sony A7 and A7R: The first full-frame compact system cameras are official

Sony has just announced the Alpha A7 and A7R, the latter of which it claims is the world's smallest interchangeable lens camera. So let's start with that.

The A7R comes with a 35mm full-frame Exmor CMOS sensor, complete with 36.4 megapixels of resolution and - as the "R" represents - no optical low-pass filter for optimum sharpness.

The new "gapless on-chip" lenses eliminate gaps between sensor nodes on the sensor's surface for an increased light collection efficiency, high resolution, sensitivity and noise reduction.

Combined with the new Bionz X processor - that's three times faster than its predecessor - the A7R also offers Full HD video (60p/25p), an audio recording level control while shooting and is said to be low-noise.

The A7R features Fast Intelligent AF that delivers quick, accurate autofocus that's fully customisable with nine buttons for you to assign 46 different functions. It also features Wi-Fi and NFC for easy pairing with a mobile. The magnesium alloy body weighs in at 407g, which Sony claims is the world's smallest and lightest interchangeable lens camera with a full-frame sensor.

The A7, by comparison, is much the same but has a lower-resolution - yet still full-frame - 24.3-megapixel Exmor CMOS sensor. It features Fast Hybrid AF, rather than Fast Intelligent AF, which combines quick phase detection with accurate contract detection autofocus.

Both cameras will work with Sony's full-frame interchangeable E-mount lenses, including two new mid-range zooms, two bright Sonnar T* primes, and a premium-quality G lens with telephoto zoom. There's also a new mount adaptor for using full-frame A-mount optics.

Both cameras will go on sale mid to late November. Pricing is yet to be announced - but we don't anticipate it will be at all cheap, given the impact of a full-frame sensor.